1. Field of Invention
This invention related to an ink jet recording apparatus and method, and more particularly to an ink jet recording apparatus with a carriage lock mechanism and a method for controlling the same.
2. Related Art
Typically an ink jet recording apparatus has a recording head which moves along a sheet of recording paper by means of a carriage, ejecting ink drops thus printing on the surface of the recording paper. Often times during printing, the carriage will be put into a waiting condition and be placed in a home position away from the printing area. While the carriage carrying the recording head is under a printing waiting condition, it moves to a predetermined home position which is located off the recording area and waits for a printing command at the home position.
Although the carriage driving mechanism applies a brake force to keep the carriage in its home position, exterior vibrations may move the carriage toward the recording area while the carriage is waiting in the home position. Furthermore, when electric power is turned off, the carriage may be able to freely move, and there is a risk that the carriage may move toward the recording area from the home position.
In order to prevent unwanted movement of the carriage, an ink jet recording apparatus is often provided with carriage lock mechanisms for mechanically fixing the carriage at the relevant home position. (For example, U.S. Pat. No. 4,695,851 and U.S. Pat. No. 4,739,847) These conventional carriage locking mechanisms are constructed in such a way that each time the carriage returns to the home position the carriage is locked. Since the driving frequency of the carriage lock mechanism is high, there are associated problems with keeping the carriage locked. One such problem is that the components of the carriage lock mechanism rapidly deteriorate.
Another problem exists when printing should be restarted immediately after a previous printing is finished, requiring the carriage lock to be disengaged. The result is decreased responsiveness of the carriage when restarting the printing.
It is desirable to have an ink jet recording apparatus which can prevent deterioration of the components caused by the carriage lock and decreased responsiveness when the printing restarts, by avoiding unnecessary carriage lock actions.